Tuning arrangement for signaling systems



y 16 1 4. I; w. FRSTRQM 2,349,0

TUNING ARRANGEMENT FOR SIGNALING SYSTEMS Filed June 22, 1959 -2 Sheets-Sheet l v Inventor": Edward W. Forsbr-om,

Wan/1 C:

His Att or'neg.

May 16, 1944. E. w. FORSTROM TUNING ARRANGEMENT FOR SIGNALING SYSTEMS 2 Sheets-Sheet 2 Filed June 22, 1959 Inventor: Edward W. Forstrom, by JWA is Attorney.

Patented May 16,

TUNING ARRANGEMENT FOR SIGNALING SYSTEMS Edward W. For-strum, Stratiord, Conan, seminar to General Electric Company, is corporation of New York Application .lune 22, 1939, Serial No. 280,565

(Cl. Mi -it) My invention relates to an improved mechanism for tuning a. signaling system and more particularly to an arrangement and. apparatus for tuning a signaling apparatus to a selected one of a number of predetermined operating frequencies.

An object of my invention is to provide an improved and simplified tuning control arrange-- ment which greatly facilitates the rapid end aouni-control operation with the condenser ill.

curate tuning of signellng systems to any one of one or more of the main tuning condensers of the system ere rotated by a. mechanical arrange ment to a. selected one of a number of predetermined settings.

An additional object of my invention is to nrovide a tuning control of the aforementioned tyne wherein each tuning operation is accomnlished. by a series of mechanical movements constituting a. tuning cycle, and my invention contemplates that the act of a person in actuating e. suitablecontrol to initiate a timing cycle is accompanied by an autometl completion of the timing cycle regardless of any subsequent and immediate actuation of one or more additional controls to initiate other tuning cycles.

'Zhe novel features which i believe to he cherecteristic of my invention are set forth with particuiarity in the appendeol'claims. lady invention however, both as to its organization and method of operation, together with further ohieccs and advantages thereof, may best he undenstood by reference to the following description taken in connection with the accompanying drawings in which Figure 1 illustrates an emsodiment of my invention, and Figure 2 illustrates a. modification thereof.

mierring more particularly to Figure 1 of the drawings, there is shown in the upper left-hand corner of this figure s tuning condenser it whose adjustment determines the operating frequency or" the signaling system, not shown, with which the condenser is used. The tuning condenser is comprised by a number of fixed plates ti and e number of movable plates it, the latter being secured to a framework 63, it and it for rotational movement about an axis it into and out of mesh with the fixed plates l i. It will be understood that while only one condenser it is shown,

The signaling system may be tuned to any desired operating frequency within a. continuous frequency hand by angular movement of the movable condenser plates 92. Ellis may he eflected through one of the shafts til, it, provided on the respective members it, it, from a. suitehletuning control, not shown. The signaling system is tuned to any one of a. number of predetermined opera-ting frequencies, here shown by way oi example as two in number, by a control arrangement now to he described.

Positioned between the end plates it, it is s chehnel-shened rocker member it; This memher is arranged to be engaged in a manner presently to he descnhed by e. selected one of a pair of 'tappets it, 26 which are supported for reciprocetory motion on respective supports 22, 2h. The suppo members 22, Zit'ere guided for reciprocal motion transverse to the saris it oi the sheits til, it by a framework, fragments of which are shown st ill, 2% and 29.. Each of the supports 22, it is normally biased to the extreme righthand end or" its trevel by a helical spring til.

Each of the supports 22, it has integrally formed. projections and 2:95 eoerimed for an adjusting screw 2t. tion is internally threaded ior threedeii engagement with the left-hand and; oi the screw it.

pin it secures the tepnet fill in piece on the support 22 while allowing the tanpet to rete-te about the axis of the pin to e. selected position of adjustment. The teppet is loosed in adjusteol position by the provision of aclamping member 32 whose upturned end. 83 encased by the end of the screw it as the letter is screwed through the threaded aperture provided in the projection it. The pin ti is so arranged that its axis coincides with the axis it of the shafts ii and it when the support 22 is moved to its extreme left-hand position to engage a selected tappet with the rocker member iii.

The pretunlng operstion in which the position of each tappet it is edjusteci to an angular position at which the signalling system is tuned to predetermined operating frequencies will now he explained by assuming that the support it end therewith the tappet it is moved to the left-hand end of its travel where the tappet it engages the top and bottom portions of the rocker memher it. The rocker member 8 ii, oi course, rotates to e position determined by the angular position The epertere in the nrojecof the ;tappet 23. The screw 23 may now be -backed%away from the upturned end 33 of the member 32 to allow the tappet 23 freely to rotate about the pin 3| and the signaling system may be tuned to a predetermined operating frequency by motion transmitted to themovable plates l2 of the .condenser l3 through a suitable operating control, not shown, connected to one of the shafts l1, l3. Movement of the movable plates of the I condenser causes a corresponding movement Of aseaoas 1 Wmbnmmumvmm theframememberflandasimilarslot 43pmvided in an additional frame member 43. The

left-hand end of the link member 43 is arranged in abutting. relation, to the projection 23 of the support 22. The right-hand end of each. link 43 has integrally formed thereon a flange 41 upon the bottom of which is positioned a spherically position of rotation about the pin 3|. After each 7 of the tappets 23 and 2| have been individually adjusted to an angular position corresponding to an operating frequency'of the signaling system, any subsequent engagement of the tappet 23 or to move the rocker member l3, and therewith the movable plates l2 of the condenser l3, to a position corresponding to the respective operating frequency.

It is obvious that the signaling system may thus be tuned to a predetermined operating frequency merely by exerting a manual force on the right-hand end of a selected screw 23 to move one of the tappets 20, 2| into engagement with the rocker member l3. This, however, requires a certain amount of physical exertion, does not lend itself readily to remote control of the tuning operation, and does not completely insure that the operated tappet will always be moved to the extreme end of its travel where the rocker member to drive a selected tappet to the extreme lefthand end of its travel. The motor is connected by gears 35 to a cam 33 whose cam surface 31 defines at least one tuning cycle. By a tuning cycle is meant that series of movements whereby a selected tappet 23 or 3| is moved from its position of rest (the position of the tappet shown in Figure 1) to the extreme left-hand end of its travel and is thereafter returned to its position of rest, this series of movements causing the tuning condenser Ill to be adjusted to that preselected position where the signaling system is tuned to a predetermined operating frequency. The cam 36 illustrated in Figure 1 has a cam surface 31 such that one complete rotation of the cam defines a tuning cycle.

The lower end of a cam follower 33 engages the cam surface 31 of the cam and is connected at its upper end to a plate 33 which is supported for rotational movement by' stub shafts 43, 4|. A helical spring 42 normally maintains the plate 33 in the position shown in Figure 1-. Upon excitation of the motor 34 through a control circuit presently to be described, the cam 36 is rotated through the gearing 35 whereupon the cam follower 33 drives the upper edge of the plate 39 with a reciprocatory motion.

In order that the motion of the plate 39 may be transmitted to a selected one of the tappets 23, 2|, a link member 43 is' provided for each of 1 2|, with the rocker member l3 causes the tappet shaped bearing member 43. A helical spring 43 is positioned between the frame member 23 and the link member 43 and normally biases the latter about its contact with the upper edge of the slot 44 to cause the bearing member 43 to engl e the upper surface of a frame member 33. The lower edge of the left-hand end of the link member. 43 is provided with a notch I l The driving connection between the plate 33 and one of the tappets 23, 2|,is completed by the operation of a selected manually actuable push button" provided for each of the tappets. Each push button 32 is supported "on the right-hand end of a lever 53 which is pivoted at 34 from the frame member 53. The left-hand curved end 33 of the lever 53 is moved by the operation of the actuated push button into engagement with the underside of the flange 41 provided on the link member 43 and causes the link 43 to move about the point of its contact with the upper edge of the slot 43 provided in the frame member 43 thereby to engage the upper edge of the plate 33 in the notch SI of the link member.

After the push button 52 has moved sufncientlyv far to engage the plate 33 with thev notch ll, an insulating pin 56 which is secured to the lever 33 engages the upper resilient arm 31 of a switch 33 to complete upon further depression Of the push button an energizing circuit for the driving motor 34 through a pair of switch contacts 33. This energizing circuit may be traced from one side of a source of power 33 through conductors ll, 32, the motor 34, the conductors 63, 34, 33, the switch contacts 59, and the conductors 33 and 31 to the other side of the power supply line.

The motor 34, when energized, drives the cam 33 through. the gearing 35 in the direction indicated on the drawings by the arrow. The cam surface 31 moves the lower end of the cam follower 38 to the right. This motion is transmitted to the plate 33 and causes the upper edge of the plate 33 to move to the left. The upper edge of the plate is, however, in engaging relation with the notch SI and thus causes a corresponding movement of the link member 43 to the left. In moving, the link member 43 drives before it the support 22 and therewith a, selected tappet 33, 2| corresponding to the particular key 32 which has been manually actuated. As the motor 34 continues to rotate, the tappet engages and moves the rocker member l9 about'its axis until the latter reaches that angular position (determined by the preadiusted angular setting of the tappet) where the condenser l3 tunes the signaling system to a preselected operatin frequency. The plate 39, the link 43,-the support 22, and the tappet having reached the leftward limit of their travel thereafter remain stationary and further movement of the cam 33 and cam follower 33 is taken up by a lost motion connection between the 63 on the upper end of the cam follower which engages an aperture 63 provided in the plate 33, by a guide pin III which loosely passes through the tappets. Each link member is guided for re- 76 an aperture in the cam follower and is fixedly seouredtotheplate ",andbyehelica-lspring It positioned on the guide pin ll between the cam ioilower 38 and a nut ll threaded onthe righthand end the guide pin.

After the cam 58 has rotated through one-belt oi the tuning cycle deiinedby the contcuroi the com surface 31, continued rotation of the cam ellows the lower end 01' the cam follower 88 to move to the left under the biasing force of the helical uprimys it, it and it. As soon as the com to has completed e. tuning cycle and is again in the position shown in the drawings, the spring it causes the leit-hcnd end oi the link 43 to move upward thereby to move the notch it out of engagement with the upper edge of the plate it.

in order thct a tuning cycle may be completed niter it hes once been initiated, on insulating bin it is secured to the side of the com it in u manner to engage the end or e. flexible spring member it, which carries the movable switch con toot it oi e. switch it. The switch sdditionoily is provided with e fixed contact ll. These switch contests ere connected in the enersis ins circuit ior the "motor it in parallel with the switch contects it oi the switch tit. Thi perellei circuit includes e conductor it and the conductors Fit, to end so. it will be evident that upon 'suiiicient rotstion oi the cam to cause the pin to move out of encasement with the resilient member it, closing oi the contects iii end ii is efiected whereupon the energizing? circuit tor the motor it is maintained closed even thoush the push button b2 may have men re leesed subsequent to the initiation oi the tunine cycle to open the switch contacts kit. The motor to time continues-to drive the com it to the end of e tuning cycle at which time the pin it esein chooses the resilient member "it to open the switch contacts lb and ii.

in the event that the push button bi is menueliy depressed for e period longer then that necessary to complete e. tuning cycle, the motor it remeins energized through the closed contests d9 of the switch bit. To prevent repented oscii letory movement oi the link member is end teppet it (or it) when this occurs, the righthsnd end of the link member 33 in its movement to the left is srranged to slide over the curved end lit or the lever iii and shut eseinst its outer periphery so that it is restrained against return movement as long as the push button iii remains depressed. As the upper edge oi the plate to thereaiter movesto'the right, the spring ruises the left-hand end oi the link member t3 to disengage the upper edge oi? the plate its from the notch ti. Thus, any further reciprocal movement of the plate it is not thereefter transmitted by the link member Qt to the teppet and its support. I

A signaling system having my invention embodied therein may be tuned to predetermined operating frequencies from points remotely sitnoted from the signaling apparatus. This is socomplished by the provision oi individual electromasnets it each positioned with its pole to under the center or a. respective link member is (in the drawings, only one such electromeenet is shown for purposes of simplicity). The link member may itself be formed of mesnetizebie material or may support a magnetizable armeture in position over the pole at of the electromagnet. In operation. the electrcmsgnet end the motor at are energized from o remote point by closure of e remotely positioned switch ti. The energizing circuit for the electromagnet is may be traced from one side of the power supply line through a conductor il, a conductor 82, the winding of the electromagnet It, a conductor 83, the contacts or the switch at, and the conductors tt and ti to the other side or the power supply line to. The energizing circuit tor the motor 35 may be traced from one side of the power supply line 80 through the conductors 8i and 82, the motor it, conductors t3 and ti, the contacts oi the switch 8i, and conductors tt and t! to the other side of line.

The energizntion oi the eiectromegnet it in this manner causes; the link member it to pivot about the bearing member It provided on its right-hand end thereby to engage the upper edge oi the plate 39 in the notch ti. The motor it being simultaneously energized drives the piste it and therewith a. selected tunnel; to move the condenser It to a preselected position correspending to e. preselected operating frequency oi the signaling system.

A modification of my invention is illustrated in Figure 2 wherein elements corresponding to like elements of Figure l are designated by like reference characters. 'i'his embodiment diiiers from Figure 1 in that the tuning condenser iii of Figure l is replaced by e. number oi trimmer condensers til, anyone of which are switched, in a manner presently to be described into the tuned circuit of the signaling system to tune the system to predetermined operating frequencies. Figure 2 shows two such trimmer condensers enclosed within s single cesins'tt, one of the condensers having a pair of terminals ti and ti while the second has a pair of term'inels it and it. The capacity of the first condenser is adjusted by a smell screw it while that of the second condenser is adjusted by a similar screw ti. The tuned circuit, not shown, oi the signaling system into which the trimmer condensers are selectively switched terminates in the conductors it and it. The conductor ti is common to the terminals it and it of the trimmer condensers while the conductor it is common to a. contact 9t and a. contact db, respectively, of a pair of switches 96 and 911. The switch 9% has a. second contact 98 which is connected by a. conductor 99 to the terminal iii oi the first trimmer condenser. The switch it likewise has as second contact iiiil which is connected by a. conductor we to the terminal til of the second condenser. Each of the switches includes a metallic bridging member Hi2 which is moved into or out of bridging engagement with the switch contacts by an actuating member lit. This latter member is constrained for reciprccel motion by suitable aperture provided in a frame member "it and a frame member mt. To provide; ease of assembly, the actuating member not is provided at its forward end with an aperture E66 into which projects a hooked end it? of e. second actuating membe ltd. The latter is constrained for longitudinal reciprocal motion by suitable slotted apertures provided in e. pair of frame members We and Mil. A helical spring ii i normally biases the actuating members Hi3 and N38 to or position where the bridging member m2 is out of bridging engagement with the switch contacts. Movement of a. selected actuating member "it to close switch contacts of a selected switch or 91 is effected by the abutting engagement of the link member it against the turned-over end H2 or the individual actuating members lot. The remainder of the the power supplyv actuating mechanism is as shown mm. 1, but

is omitted from the present figure merely for purposes of simplifying the drawings.

It will be understood that the manual depres-- Ill, the latter being normally biased into engaging position with the notches by a helical spring I is. It will be understood that the movement of a selected actuating member I" causes a downward movement of the latch bar I ll against the action of the spring I I suiiicient to release any actuating member liil previously latched in switch-closing position.

In the claims which follow the general term "actuator" has been used to define that combination of elements which effects the tuning of a signaling system to preselected operating frequencies merely by the actuation of a particular element in the combination.

While I have shown particular embodiments of my invention, it will of course be understood that I do not wish to be limited thereto since many modifications may be made in the several elements and their arrangement, and I contemplate by the appended claims to cover all such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. The combination, in a tuning system, of a plurality of parallel members arranged for reciprocation longitudinally thereof, each member being arranged upon reciprocation to tune said system to a corresponding frequency, an actuator common to all of said members and having motion when actuated in a direction longitudinal 01' said members, a motor to drive said actuator, a plurality of keys, each key corresponding to one of said members, and aplurality of longitudinally reciprocating rocker members each positioned between a respective key and a corresponding one of said parallel members and arranged when moved longitudinally to engage the corresponding one of said first members to actuate it to tune said system, each key being arranged upon operation thereof to rock its corresponding rocker member into engagement with said actuator and to energize said motor, whereby said motor operates said actuator and drives said rocker member longitudinally of itself to engage one of said first members thereby to tune said system to a frequency corresponding to the actuated key.

2. The combination, ini'a tuning system, of aplurality of control members, each of said memhere being arranged upon longitudinal movement thereof to tune said system to a corresponding frequency, said control members being arranged in parallel, an actuator extending at right angles to all of said members and arranged to have movement longitudinally of said members, a plurality of connector members and keys, one key and connector member corresponding to each of said control members, each connector member being arranged to be actuated ,by its respective I said receiver to the corresponding frequency, a

motor driven cam and follower, said follower being arranged for oscillation by said cam, a plurality of keys, each key corresponding to one of said reciprocally movable elements, means actuated by said key mechanically to connect the corresponding reciprocally movable element to said follower for movement therewith, and to energize said motor, and means to maintain said motor energized during one oscillation of said follower and of the reciprocally movable element connected thereto by actuation of the key actuated.

4. The combination, in a mechanical tuning assembly for radio receivers, of a plurality of push rods arranged in parallel relation, each of said rods being arranged when actuated to tune said receiver to a corresponding frequency, a plurality of keys and a plurality of rocker members, each rocker member extending between a corresponding key and push rod for engagement therewith, a push member extending across all of said rocker members but normally disengaged therefrom, said rods, keys and members being so constructed and arranged that upon actuation of any key the corresponding rocker bar is rocked into driving engagement with said push member, and is driven thereby longitudinally of the corresponding push rod to operate said corresponding push rod to tune said receiver, and means responsive to actuation of any of said keys to actuate said push member to effect said tuning.

EDWARD W. FORSTROM. 

